Abstract

The Atlantic Motorway, AP-9, crosses the Vigo estuary by means of a 400-m span cable-stayed

bridge over the Rande Strait. This bridge was built between 1973 and 1977, and opened to traffic in

1981. In 2006, the average daily traffic reached 47 000 vehicles, close to its effective capacity and

therefore resulted in frequent traffic congestion conditions.

In order to increase the bridge’s traffic capacity, feasibility studies were carried out. After technical,

aesthetic and economic comparative analyses, the most favourable solution found was a widening

project. The widening solution consists of two new external decks positioned along both the outer

sides of the existing deck next to the main piers. This system will allow bridge-widening works

without both interrupting the traffic on the existing bridge and affecting the Vigo estuary, a very

valuable zone from a natural environmental and landscape perspective.

Keywords: Bridge widening, cable-stayed bridge, long span, wind tunnel, erection process.